SYNOPSIS

DESCRIPTION

This vnode call may be used to set specific named extended attribute for
a file or directory.
Its arguments are:
vp The vnode of the file or directory.
attrnamespace
Integer constant indicating which extended attribute namespace the
attribute name is present in.
name Pointer to a null-terminated character string containing the
attribute name.
uio The location of the data to be read or written.
cred The user credentials to use in authorizing the request.
td The thread setting the extended attribute.
The uio structure is used in a manner similar to the argument of the same
name in VOP_WRITE(9). However, as extended attributes provide a strict
"name=value" semantic, non-zero offsets will be rejected.
The uio pointer may be NULL to indicate that the specified extended
attribute should be deleted.
The cred pointer may be NULL to indicate that access control checks are
not to be performed, if possible. This cred setting might be used to
allow the kernel to authorize extended attribute changes that the active
process might not be permitted to make.
Extended attribute semantics may vary by file system implementing the
call. More information on extended attributes may be found in
extattr(9).

LOCKS

The vnode will be locked on entry and should remain locked on return.

RETURNVALUES

If the extended attribute is successfully set, then zero is returned.
Otherwise, an appropriate error code is returned.

ERRORS

[EACCES] The the caller does not have the appropriate
privilege.
[ENXIO] The request was not valid in this file system for the
specified vnode and attribute name.
[ENOMEM] Insufficient memory available to fulfill request
[EFAULT] The uio structure refers to an invalid userspace
address.
[EINVAL] The name, namespace, or uio argument is invalid.
[EOPNOTSUPP] The file system does not support VOP_SETEXTATTR().
[ENOSPC] The file system is out of space.
[EROFS] The file system is read-only.